an entrant for a race that actually competes in it
a bank or stockbroker's messenger
(usu in combination) somebody who smuggles or distributes illicit or contraband goods
a gun-runner
a straight piece on which something slides, e.g.:
a longitudinal piece on which a sledge or ice skate slides
a groove or bar along which something, e.g. a drawer or sliding door, slides
a horizontal stem from the base of a plant that buds to produce new plants; = stolon
a long narrow carpet, e.g. for a hall or staircase
a narrow decorative cloth for a table or dresser top
do a runner
Brit, informal to leave in haste, esp to avoid paying for something or to escape the scene of a crime